Method for cullet qualtiy grading

ABSTRACT

A method for grading the quality of cullet. Some embodiments include methods for generating a statistically significant sample of material from a collection of cullet contaminated with waste. Other embodiments include methods for evaluating various qualities of the sample with relatively simple techniques. Yet other embodiments include a uniform and reasonably simple method for communicating the results of the evaluation among different parties.

CROSS REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority to U.S. ProvisionalPatent Application Ser. No. 61/223,311, filed Jul. 6, 2009, entitledMETHOD FOR CULLET QUALITY GRADING, incorporated herein by reference.

FIELD OF THE INVENTION

Various embodiments of the present invention pertain to methods fordetermining the quality of cullet, and in particular to methods foranalyzing the color and sizing of the cullet, organic material on thecullet, or inclusion of non-glass materials.

BACKGROUND OF THE INVENTION

The multifunctional role of cullet as an endless cradle to cradlesustainable material has resulted in its increased use within the glassindustry. This is even more pronounced in light of recent spiralingenergy prices. However, availability of high quality post consumercullet is a challenge due to contamination during the recycling process.So far to the author's knowledge, there are no systematic methods todetermine the type of contamination and also to express the severity ofsaid contamination in a truck load or a pile of cullet. This work in oneembodiment establishes a practical quality index to specify culletquality by type and severity of contaminants. This coding method can beused by all parties involved in the life cycle of cullet (i.e. culletsuppliers and glass manufacturing industries).

Cullet can be used in the glass manufacturing process in any percentageup to ˜90% depending on availability, quality and price. The advantagesof addition of cullet to raw batch can be summarized as:

-   1. Cullet accelerates the melting process by wetting the batch    materials and hence aiding decompositions and/or reactions to take    place faster.-   2. Based on empirical data, every 10% of cullet can result a saving    of ˜3-4% in energy consumption.-   3. Use of cullet improves sustainability by reducing the quarrying    of virgin raw materials; every 100 tons of cullet results in a    reduction of 120 tons of virgin materials, assuming normal fusion    loss factors.-   4. As a result of the aforementioned benefits of reducing energy and    reduction of raw materials, cullet results in reduced emitted gases    like CO2, SOx and NOx.

Various embodiments of the present invention establish a practicalquality index to specify quality of cullet as far as type and severityof contaminants. Some embodiments of the inventive method of codingdescribed herein can be used by all parties in the life cycle of culleti.e. cullet suppliers and glass manufacturing industries.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graphical representation particle size vs. LOI percentageshowing the results of tests done on 6 samples showing that LOIincreases within the smaller pieces of cullet.

FIG. 2 is a graphical representation of the results of measured LOI at500 degrees C. versus LOR on 27 different cullet samples, and is anapproximate correlation to convert measured LOR to LOI.

FIG. 3 is a schematic representation looking downward on a pile ofcontaminated cullet surrounded by a plurality of split samples.

FIG. 4 is a schematic representation looking down on a mixture of splitsamples separated into four sectors.

FIG. 5 is a block diagram of a method according to one embodiment of thepresent invention.

FIG. 6 is a block diagram of a method according to one embodiment of thepresent invention.

FIG. 7 is a block diagram of a method according to one embodiment of thepresent invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT

For the purposes of promoting an understanding of the principles of theinvention, reference will now be made to the embodiments illustrated inthe drawings and specific language will be used to describe the same. Itwill nevertheless be understood that no limitation of the scope of theinvention is thereby intended, such alterations and furthermodifications in the illustrated device, and such further applicationsof the principles of the invention as illustrated therein beingcontemplated as would normally occur to one skilled in the art to whichthe invention relates. At least one embodiment of the present inventionwill be described and shown, and this application may show and/ordescribe other embodiments of the present invention. It is understoodthat any reference to “the invention” is a reference to an embodiment ofa family of inventions, with no single embodiment including anapparatus, process, or composition that should be included in allembodiments, unless otherwise stated.

The use of an N-series prefix for an element number (NXX.XX) refers toan element that is the same as the non-prefixed element (XX.XX), exceptas shown and described thereafter. As an example, an element 1020.1would be the same as element 20.1, except for those different featuresof element 1020.1 shown and described. Further, common elements andcommon features of related elements are drawn in the same manner indifferent figures, and/or use the same symbology in different figures.As such, it is not necessary to describe the features of 1020.1 and 20.1that are the same, since these common features are apparent to a personof ordinary skill in the related field of technology. Although variousspecific quantities (spatial dimensions, temperatures, pressures, times,force, resistance, current, voltage, concentrations, wavelengths,frequencies, heat transfer coefficients, dimensionless parameters, etc.)may be stated herein, such specific quantities are presented as examplesonly, and further, unless otherwise noted, are approximate values, andshould be considered as if the word “about” prefaced each quantity.Further, with discussion pertaining to a specific composition of matter,that description is by example only, and does not limit theapplicability of other species of that composition, nor does it limitthe applicability of other compositions unrelated to the citedcomposition.

The U.S. and Europe have different methods for collecting and usingcullet. In Europe, it is common for cullet to be entirely separate fromother waste streams, such as paper, metals, and organics (such as foodwaste). In some cases, cullet is even separated by color. In such awaste collection system, there is relatively little contamination of thecullet with any of the other waste streams. Further, if a glassmanufacturer needs to know how to present the proper mix of ingredientsto the glass furnace, it is relatively straight forward to mix thecullet with various correcting agents.

In contrast, recycled material in the U.S. is largely a co-mingled,single stream of waste from the house or curbside to the wasteprocessors. These processors must separate as best they can those wasteproducts that have economic value, such as cullet and aluminum. Evenafter such gross processing of the single stream of waste products, theseparated waste streams can still contain significant amounts ofco-mingled waste. For example, the separated cullet may have come fromfood containers, in which case there is food residue on the cullet.Further, some objects such as porcelain, ceramics, and stones are oftenstill co-mingled with the cullet. The cullet may further contain variouspieces of metal that were not of a size, composition, or character tohave been successfully separated out.

Therefore, in the U.S. the cullet provided by waste processors to glassmanufacturers typically contains unknown, significant, and variableamounts of contaminant. In order to maintain the economic viability ofrecycling the cullet, the cullet should not have too many contaminantsthat will damage the glass manufacturers facilities, or result inundesirable glass containers. If the degree of contamination is notknown, then damage to the manufacturing equipment or fabrication ofunsafe containers can lead to economic consequences that overwhelm theenergy savings and beneficial environmental effects by the use ofcullet.

In addition, if it is too expensive to assess, grade, and categorize thecontaminated cullet, then the price of the cullet can be high enough tooffset the beneficial environmental aspects of the cullet usage. As oneexample, if the waste processor is required to have expensive treatment,sampling, and chemical analysis facilities, then he will commensuratelyincrease the price of his cullet, which results in reduced usage.

A further complication of contaminated cullet prepared by wasteprocessors and sold to glass manufacturers arises from thenon-homogeneous nature of the contaminated cullet. Often, the cullet isnot mixed, and one local area of a pile of contaminated cullet may haveexcessive types of particular contamination (such as green glass) thatis not representative of the entire pile. Therefore, if samples aretaken from the pile for further analysis, the samples will be skewed ifcare is not taken to be statistically significant in the samplingmethod.

Yet another complication in the U.S. of contaminated cullet is the lackof a common grading and categorization method between cullet providersand cullet users. One embodiment of the present invention pertains to agrading method for assigning a multidigit number as representative ofthe quality of the cullet within a specific quantity (or pile) ofcontaminated cullet. In one embodiment, the grading method includes fourdigits, with one digit representative for various grades of each of thecolor; organic and moisture content; porcelain, ceramics, stones (PCS)and metals and different glasses; and the size of the particles ofcullet. One embodiment pertains to assessing each of these fourqualities of the cullet pile with numbered grades (such as a grade of 1being best and a grade of 6 being worst). It is appreciated that thedifferent quality categories could be represented by letters or symbols,and further that the order of the four qualities within the multidigitnumber is arbitrary. Further, in some situations where a supplier isknown to be consistent with regards to one or more qualities, thatcullet supplier may be asked to only provide grades in the inconsistentqualities.

One embodiment of the present invention pertains to a method forconsistently grading a quantity of cullet without the need to resort totesting requiring specialized laboratory facilities. In one embodiment,the organic content of the cullet is established by drying arepresentative sample of the cullet, weighing the sample, rinsing thesample with a fluid such as water, and re-weighing the sample. Themethod results in the determination of a weight loss on rinsing (LOR)that is useful in predicting the organic content of the entire sample.

Yet another embodiment of the present invention pertains to a method forestablishing a statistical basis for analyzing the presence of variouscontaminants in a load of cullet. The method includes creating a firstnumber of pilot samples taken from different locations of the load. Themethod includes making a first assessment of a contaminant from thefirst pilot samples. In some embodiments, the first assessment is forthe number of pieces of porcelain, ceramics, stones, and metals. In someembodiments, the first number of pilot samples is reduced to astatistically significant yet reduced second number of piles. From thissmaller second number of samples, additional assessments can be made ofthe cullet, such as the color content, size content, or organic content.

Yet other embodiments of the present invention pertain to a method forestablishing statistically significant samples from a load of cullet,such as a load of cullet and other waste material and recyclablematerial dumped from a truck and into a pile.

In one embodiment, the method includes taking a number of pilot samplesfrom a predetermined height of the pile. In one embodiment, thepredetermined height is about half-way from the base of the pile to thetop of the pile. The method further includes taking a number of pilotsamples around the circumference of the pile. In some embodiments, thesamples are taken from the pile at approximately equally spacedlocations around the circumference of the pile. In still furtherembodiments an equal number of samples are taken.

The method further includes eliminating at least a pair of samples thatare spaced apart and on opposite sides of the pile. The remainingsamples are then remixed into a second central pile. A secondpredetermined number of pilot samples are taken from the second file.Preferably, the second number of samples are taken at locations aroundthe second pile that are circumferentially equidistant from one another,and further preferably from a location intermediate of the base and thetop of the second pile. From this second arrangement of pilot samples, apair of samples from opposite sides (i.e., about 180 degrees oppositeeach other) are removed.

This aforementioned process of taking equally spaced samples,eliminating oppositely placed samples, and remixing the remainingsamples can continue until the remaining sample size is suitable forfurther analysis of color, size, or organic content. Preferably, in thefinal step of the process there are only two samples remaining that arein opposite quadrants of the final central pile. In yet otherembodiments the final mixture of samples is spread evenly over an areaand divided into equal sectors (or in some embodiments, for equalquadrants). Preferably, two opposite sectors (or two opposite quadrants)of the final mixed sample are retained. One sector is used for furthermeasurements, and another sector is kept for reference purposes.

One embodiment of the present invention pertains to a method forassessing the water content of a batch of cullet glass. In oneembodiment the method includes determining the weight loss of ameasurement sample that occurs as a result of drying. In one embodiment,the measurement sample is first weighed in its contaminated state. Themeasurement sample is then dried in air at a temperature preferablychosen to evaporate water (such as about 110 degrees C.), but not sohigh a temperature as to oxidize any organic contaminants. After drying,the measurement sample is weighed again. This loss in weight can beexpressed as a percentage of the total weight of the sample. In someembodiment this percentage loss is referred to as the loss on rinsing(LOR), and can be used to adjust the total weight of the pile of cullet,especially in those applications where the cullet is purchased on aweight basis.

Yet another embodiment of the present invention pertains to a method forassessing the organic content of a batch of cullet glass. In oneembodiment the method includes rinsing a measurement sample of the batchwith water. In some embodiments the temperature of the water is slightlyelevated to about 80 degrees C. The rinsing continues until the waterdraining from the measurement sample is clear, indicating that organiccontaminants have been washed away. The sample is dried, and the weightof the rinsed and dried cullet is compared to the weight of the drycullet prior to rinsing. The measurement sample's weight loss on rinsing(LOR) can be used to categorize the pile (or initial batch) of culletwith regards to its contamination by organic materials (such as food,paper, etc.).

Further, it has been found that LOR correlates generally to the weightloss on ignition (LOI) of the sample. In those cases where LOI is usedto assess cullet, the LOR can be substituted and used in the assessment.

Yet another embodiment of the present invention pertains to methods forassessing the characteristics of a collection of cullet that can be donesimply and without expensive equipment, yet still protecting the glassfurnace. One embodiment includes a method for acquiring a representativesample of raw cullet (i.e., contaminated) from a larger collection ofcullet. In one embodiment, the method includes providing a quantity ofraw cullet, such as a truckload of cullet from a waste materialprocessor. The truckload is dumped onto a surface in a pile. Samples aretaken from a point midway between the top of the pile and the bottom ofthe pile, so as to minimize biasing of contaminants in the sample due tosettling of the raw cullet. Further, samples are taken fromcircumferential points generally equidistant around the mid-height ofthe pile. These pilot samples are then arranged relative to each otherin a manner generally corresponding to the circumferential location ofthe pile from which they were taken. In this way, if a particularlocation within the pile is biased (such as to include large amounts ofa particular color of glass), the final effect of the biasing on thehomogeneity of the measurement sample will be minimized.

The more common ways of categorizing contaminant materials in cullet areusually based on the type of contaminants. This paper presents variousmethods of detection of contaminants resulting in a simple way of codingto specify the quality of large volume piles of cullet.

It is common practice in the glass industry to use mixed cullet in theproduction of colored glasses such as amber and greens. But variation ofthe proportions of different colors can result in problems. For example,in a 3 mix cullet the proportions of green, amber and flint should beconsistent to assure the consistency of quality as well as the color ofthe finished glass products. Flint cullet is used to help control theredox of colored glasses. Therefore, uncontrolled variations of flintcullet will result in fluctuations in the redox from the targeted valuein the batch formulation. In flint glass manufacture, the existence ofcolored cullet would also affect the color parameter mainly as a resultof presence of Chromium, Iron Oxides, Sulfur, and Carbon from coloredcullet.

Visible organics, paper, wood, cork, plastics, rubbers and even fabrics,are not uncommon in many cullet sources. Invisible organics such as fat,oil, sugar and other carbohydrates in post consumer cullet areinevitable contaminants. Unknown and uncontrolled amounts of organics incullet will directly affect the redox condition of the glass, resultingin refining issues as well as color variations. Based on empiricalexperiments, the following relations can be assumed for differentorganics:

1 unit wt. of carbon=20 units paper=4 units plastic=0.8-0.9 units fat oroil=1 unit sugar

Common practice for reducing organics in cullet is to stock the culletfor at least 4-6 weeks. This, together with enough moisture, allowsdisintegration of much of the organic material within the pile. Byallowing time for disintegration, the level of organics tend to aconstant value and in this way the glass technologist can make moreaccurate adjustments with regards to the amount of carbon in the batchto ensure the required redox is achieved.

PCS contaminants (porcelain, ceramics, and stones) are the major causeof stones in finished glass products. The majority of stones found infinished products derive from PCS contamination in the cullet stream.

Metals, both Ferrous and non-Ferrous (Lead, Aluminum), have differenteffects on the quality of finished product as well as on the life offurnace refractories. For instance, large pieces of Iron result indownward drilling on the bottom paving refractories, resulting in glassrunning between the insulation layers, and eventually causing bottomfailures. Lead, usually from wine bottle seals, and light bulbcomponents, increases the amount of heavy metals content in finishedglass product. Metallic Aluminum causes so called Silicon Balls byreducing SiO2 to elemental Si.

The presence of cullet with different fundamental chemistry in the hostglass is a major cause of knots. In the case of production of Soda-Limeglass, other glasses such as Aluminosilicate, Borosilicate, LeadCrystals and Vitreous Silica within the feed cullet can create knotsand/or cords due to their higher melting temperatures and higherviscosities at normal melting temperatures of Soda-Lime glasses.

Another consideration in the use of cullet within the glass industry iswith regards to the size of the cullet pieces. In some instances, it ispreferred to use fine ground cullet with the logic that stones andceramic contaminations will be ground to smaller pieces and hence therisk of finding their way to the finished product is reduced. In yetother situations, it is considered that ground cullet carries aconsiderable amount of “invisible” organics that affect redox.

In one embodiment of the present invention, it is contemplated that thesize of the cullet pieces are between about ¼″ and about 2″ indimension. Pieces larger than about 2″ often result in blocking withinconveying chutes while pieces smaller than about ¼″ are consideredsusceptible to carry a large proportion of “invisible organics” due tothe high surface area to volume ratio. FIG. 1 shows organic contents insmaller pieces of cullet start picking up among the sizes smaller than¼″.

Based on the previously mentioned categories of cullet contaminants, oneembodiment of the present invention contemplates a system of codingindicates the type and the severity of each contaminant. This codingtakes the form of a multidigit number, such as a 4 digit number, whichcan be referred to in some embodiments as the COPS Code. Each digitrepresents one of the following parameters:

-   -   C: for Color    -   O: for Organics    -   P: for PCS (Porcelains, Ceramics and Stones), metals and other        types of glasses, and    -   S: for Size of the cullet pieces        Where each letter would be replaced with an integer from 1 to 6        in which 1 would indicate the best grade and 6 would be the        worst grade.

In one embodiment of the present invention, a representative sample istaken for the measurements, such as from a truck load of cullet,unloaded on the ground. The unloaded pile is preferably divided into 8zones as shown, looking from the top, as shown in FIG. 3.

Using a scoop with the approximate capacity of 6 pounds take 1 sampleform each spot from the mid height of the pile by dipping the scoopinside the pile. Therefore, the total sample will be around 48-50pounds. Spread the sample on a clean area next to the cullet pile andlook for the PCS, metals and other types of glasses which are largerthan ¼″. Mix the sample in place by using the scoop and make a cone.Divide it into 4 sections as shown in FIG. 4. Discard the 2 oppositequadrant and choose the other. Now 24 pounds of sample is left. Repeatsteps 4-6 till around 3 pounds of sample is left on the ground. Now takethis sample to the lab (any room used for the rest of measurements). Forthe last time split the 3 pound sample into 4 sections. Each section nowis around ¾ of a pound or 12 oz. or 340 gr. which is called small splitsample throughout this paper. Save and label one part for futurereferences and use each of the other parts for different measurements.

The following is the sequence of the measurements for each categoryaccording to one embodiment. With regards to PCS, Metals and DifferentGlasses, foreign materials in the cullet are divided into 2 differentparts with respect to the size of pieces. One part pertains to piecesgreater than ¼″ which usually have the potential to appear as aninclusion defect in the final glass product, and the other part refersto pieces smaller than ¼″ which usually will get melted in the furnaceand subsequently pose less of a risk for inclusions in the finishedglass product.

For sizes greater than ¼″ use the entire 48 lb representative sample (asshown in FIG. 3) before splitting into split samples. Then count thenumber of big sizes that are almost equal or greater than ¼ inch in onedimension. The material can be categorized according to, in oneembodiment, Table 3 for criteria of grading.

For particles smaller than ¼″ (if any) one of the small measured samples(as shown in FIG. 4) will be used for measuring the weight percentage ofthe fine particles over the total wt of the sample. See Table 3 forcategorizing of each grade.

With regards to size of the cullet pieces, using one of the small splitsamples (as shown in FIG. 4), the technician is to then weigh the sample(W total). The technician then segregates the pieces which are smallerthan ¼″ and bigger than 2″ and weigh (W off size). Followingsegregation, the technician calculates the weight percentage of off sizecullet pieces with respect to the total weight.

With regards to color, in a flint cullet, any color other than flintwould be off color, or in a 2 mix cullet like green and amber if youragreement with the supplier is to receive a proportion of 40/60 then anydeviation from the expected proportions will be considered as off color.

To measure the percentage of off color the technician uses thesegregated part (pieces between ¼ and 2″) from the above sample used forsize of the cullet pieces. The technician weighs the sample. Thetechnician then segregates the different colors and weighs each part.Following segregation, the technician calculates the weight percentageof each part versus the total wt of the sample. Table 1 shows thecriteria for the color variations for each grade.

With regards to organics and moisture, there are three recognizedmethods for the determination of the amount of organics in cullet: Losson Ignition (LOI), Chemical Oxygen Demand (COD) and Partial pressure ofOxygen in a cullet melt. LOR (Loss on Rinsing) is a method according toone embodiment of the present invention that avoids some of thecomplications of the aforementioned other methods. Some of the othermethods, such as LOI, can require the use of equipment that the culletsupplier may not have. In contrast, the LOR method in some embodimentsuses methods and equipment that do not require special training orskills.

To measure LOR take one of the measured samples of the total sample (thepile) and perform the following acts on the measured sample:

-   -   I. Weigh the sample (W₁).    -   II. Dry the sample at 110° C. for 15-20 minutes and cool it        down.    -   III. Weigh the sample again (W₂).    -   IV. LOD %=(W₁−W₂)/W₁×100    -   V. Place the sample in a 100 mesh screen (or a flat dish) and        rinse the sample with hot water (80° C.) till the water runs        clear—if using the flat dish make sure not to lose the fine        particles of cullet counting them as the organics.    -   VI. Dry the sample again at 110° C. for 15-20 minutes and cool        it down.    -   VII. Weigh the sample (W₃).    -   VIII. LOR %=((W₂−W₃)/W₂×100.

The following four tables present various categories for assessing theaforementioned tests on the samples of cullet. Table 1 refers to thegrading criteria and categories for evaluating how much the pile ofcullet deviates from the desired color characteristics. For example, itmay be desired that the cullet be 100 percent flint. In such a case agrade of 1 would be established for samples having three percent oftheir cullet (by weight) being of a non-flint color. As yet anotherexample, it may be desirable to obtain cullet that is a combination ofgreen and amber (for example, a 60 percent/40 percent split of green andamber, respectively). In this case, green and amber measurements of 56.5percent and 43.5 percent, respectively, would result in the materialbeing categorized with a grade above 2.

Table 2 presents the criteria for grading of organics and moisture in apile of cullet. In one embodiment, each of the six grades can be basedeither on the LOD measurement or the LOR measurement. Further, in Table2 as well as the other tables, it is to be appreciated that the variouscriteria for grading are by way of example only, and are not intended tobe limitations to any of the inventions disclosed or claimed herein.

TABLE 1 Grading criteria and categories for off color. Grade Criteria 1off color ≦3% 2 3% < off color ≦ 4% 3 4% < off color ≦ 5% 4 5% < offcolor ≦ 6% 5 6% < off color ≦ 7% 6 off color >7%

TABLE 2 Grading criteria and categories for organics and moisture.Grade* Criteria 1 0.5% < LOD ≦ 1.0% AND/OR LOR ≦ 1.0% 2 1.0% < LOD ≦1.5% AND/OR 1.0% < LOR ≦ 1.5% 3 1.5% < LOD ≦ 2.0% AND/OR 1.5% < LOR ≦2.0% 4 2.0% < LOD ≦ 2.5% AND/OR 2.0% < LOR ≦ 2.5% 5 2.5% < LOD ≦ 3.0%AND/OR 2.5% < LOR ≦ 3.0% 6 LOD > 3.0% AND/ORLOR > 3.0%

Table 3 presents six grades for categorizing the amount of porcelain,ceramics, stones, metals, and different glasses (such as borosilicate)that was determined to be in the measured sample. In the example ofTable 3, grade 6 is a category 4—those piles of contaminated cullet thatinclude a large number of large size objects, or a large weightpercentage of small objects. With regards to the larger size objects,these can result in significant inclusions and weaknesses in a finalglass product, and should therefore be minimized. With regards tocontaminated cullet piles having a large weight percentage of suchobjects, it is appreciated that these are often miscellaneouscontaminants sometimes referred to as dirt.

TABLE 3 Grading criteria and categories for PCS, metals and differentglasses. Grade* PCS, Metals and Different Glasses 1 Large size; 0-1count AND/OR Small size ≦ 0.5 wt. % 2 Large size; 2 count AND/OR 0.5 <Small size ≦ 1.0 wt. % 3 Large size; 3 count AND/OR 1.0 < Small size ≦1.5 wt. % 4 Large size; 4 count AND/OR 1.5 < Small size ≦ 2.0 wt. % 5Large size; 5 count AND/OR 2.0 < Small size ≦ 2.5 wt. % 6 Large size; 6or more count AND/OR Small size > 2.5 wt. %

Table 4 shows six categories of grades that refer to cullet pieces thatare either too small or too large. It has been determined that too manylarge pieces of cullet can impede the conveying systems that provide thecullet and other materials to the furnace. With regards to small pieces,it has been found that too many small pieces can result in high degreesof organic contamination.

TABLE 4 Grading criteria and categorizing for sizing of cullet pieces.Grade Size of cullet pieces 1 off size ≦20% 2 20% < off size ≦ 30% 3 30%< off size ≦ 40% 4 40% < off size ≦ 50% 5 50% < off size ≦ 60% 6 offsize >60%

FIGS. 5, 6, and 7 show various embodiments of cullet evaluation method100. Method 100 includes the act 110 of placing raw or contaminatedcullet in a single pile. This may be all or part of a load ofcontaminated cullet within a truck, or piles created in other methods.Act 120 is to take a sample from predetermined circumferential locationat a predetermined height of the pile. Act 130 includes taking the splitsample from act 120 and placing it adjacent to the pile at about thesame circumferential location. Act 140 includes repeating act 120 and130 preferably at a plurality of equidistant circumferential locations,and preferably from about the same predetermined height of the pile.These additional split samples (as best seen in FIG. 3) can be thoughtof as being arranged along north, south, east, and west directions.

Act 150 includes counting the number of large solid contaminants in allof the individual split samples as shown in FIG. 3. This counting oflarge size particles is assessed within Table 3, as shown in act 160.

Following the evaluation of large solid contamination, act 170 includesmixing together the split samples (such as the eight split samples shownin FIG. 3) into a single mixture. The single mixture is then dividedinto four sectors, as expressed by act 180 and shown in FIG. 4. Twosectors that are opposite from one another are removed and placed backin the original pile (the sectors being indicated by cross hatched linesin FIG. 4). There are now two samples that are opposite each other interms of an X-Y grid. In some embodiments, one of the sectors willinclude the measured sample that is used in act 220. In yet otherembodiments, and as expressed in act 200, these two opposite sectors areagain mixed, split, and separated in a repeat of acts 170, 180, and 190.

Further details of the measurement act 220 are shown in FIGS. 6 and 7.Acts 230 to 270 include an assessment of the weight percentage ofdifferent colors within the measured sample. The color weightmeasurements are compared to the desired color weight mix as expressedin Table 1.

Acts 280 to 310 pertain to the categorization and grading of culletpieces in the measurement sample that are either too small or too large.As expressed in act 310, the percentage of cullet pieces smaller than apredetermined size or larger than a different predetermined size aregraded according to the categories of Table 4.

FIG. 7 shows additional aspects of measurement method 220. Acts 320,330, and 340 include separating the smaller pieces of porcelain,ceramics, stones, metals, and other glasses, determining their weightpercentage as a total of the measurement sample, and categorizing thepile according to grades of table 3.

Steps 350 to 440 pertain to establishing values for the LOD and LORqualities the pile. Act 350 includes measuring the weight of themeasurement sample. Act 360 includes drying the sample, such as at 110degrees C. and then cooling it down. The sample is again weighed, and inact 330 the percentage of weight lost by drying is established.

In some embodiments, act 390 follows act 380, and includes rinsing thedried measurement sample. The rinsing is continued until the rinsingfluid is considered to be free of contaminants. In acts 400 and 410 therinsed sample is dried and weighed, respectively. Act 420 includesdetermining the percentage of weight lost by the rinsing. Act 430includes categorizing the pile based on the grading criteria of Table 2.Act 440 includes using the data of FIG. 2 to correlate LOR to LOI.

While the inventions have been illustrated and described in detail inthe drawings and foregoing description, the same is to be considered asillustrative and not restrictive in character, it being understood thatonly certain embodiments have been shown and described and that allchanges and modifications that come within the spirit of the inventionare desired to be protected.

1. A method for evaluating cullet, comprising: providing a pile ofcullet contaminated with other waste products; taking a pilot samplefrom each of a plurality of predetermined circumferential locationsaround the pile placing each pilot sample at approximately the samecircumferential location outside of the outer periphery of the pile aswhere the particular pilot sample was taken; performing a firstevaluation of the number of non-glass objects larger than apredetermined size in at least some of the pilot samples; mixing thepilot samples; distributing the mixed pilot samples onto a surface;dividing the distributed pilot samples into a plurality of substantiallyequally sized sectors; and performing a second evaluation on the samplematerial within one of the sectors of one of cullet color, organiccontamination, or cullet size.
 3. The method of claim 1 wherein saidmixing is after said performing a first evaluation.
 4. The method ofclaim 1 wherein the pile has a top and a bottom and said taking a pilotsample is from a height about midway from the bottom to the top.
 5. Themethod of claim 1 wherein the predetermined circumferential locationsare about equidistant from one another.
 6. The method of claim 1 whereineach said sample is of approximately the same volume.
 7. The method ofclaim 6 wherein said providing includes a scoop and said taking a pilotsample is with the same scoop.
 8. The method of claim 1 wherein theevaluation of cullet size is to devalue sizes smaller than apredetermined size.
 9. The method of claim 8 wherein the predeterminedcullet size is about one-fourth inch.
 10. The method of claim 1 whereinthe evaluation of cullet size is to devalue sizes larger than apredetermined size.
 11. The method of claim 10 wherein the predeterminedcullet size is greater than about 2 inches.
 12. A method for evaluatingcullet, comprising: providing a quantity of cullet contaminated withother waste products; removing a sample from the quantity; counting thenumber of non-glass objects in the sample larger than a predeterminedsize; associating a first numerical grade with the number; separatingfrom the sample cullet of one of the colors of amber, green, or flintand determining the weight fraction of that color within the sample;associating a second numerical grade with the weight fraction; andevaluating the usefulness of the quantity in a glass furnace using thefirst numerical grade and the second numerical grade.
 13. The method ofclaim 12 which further comprises drying the sample and determining thefraction of weight lost by drying and associating a third numericalgrade with the dried weight fraction, wherein said evaluating uses thethird numerical grade.
 14. The method of claim 12 which furthercomprises rinsing the sample and determining the fraction of weight lostby rising and associating a third numerical grade with the rinsed weightfraction, wherein said evaluating uses the third numerical grade. 15.The method of claim 12 which further comprises rinsing the sample anddetermining the fraction of weight lost by rising and associating therinsed weight fraction with the weight loss by ignition, wherein saidevaluating uses the weight loss by ignition.
 16. The method of claim 12which further comprises determining the weight percentage of culletparticles smaller than a predetermined size in the sample andassociating a third numerical grade with the small size weight fraction,wherein said evaluating uses the third numerical grade.
 17. The methodof claim 16 which further comprises determining the weight percentage ofcullet particles larger than a second predetermined size in the sampleand associating the third numerical grade with the large size weightfraction and the small size weight fraction, wherein said evaluatinguses the third numerical grade.